Self-cleaning filter system

Abstract

A self-cleaning filter apparatus including a first filter unit and a second filter unit. Each filter unit includes a housing forming an internal cavity, a liquid agitator means rotatably mounted within the cavity and adapted to be rotated by a rotating means external of the housing. A flat filter element is mounted in supported relation between the housing and a connected housing cap with a filter face openly exposed to said cavity. The housing forms inlet and outlet liquid flow passages for circulating a liquid sample through the cavity around the agitator and into filterable contact with the filter face. The agitator means agitates the liquid sample within the cavity and forces a portion of the liquid sample in a washing action across the filter face. The housing cap forms a liquid filtrate passageway for withdrawing a filtered sample of the liquid sample through filter element. A drive is connected to concurrently drive the agitators of both first filter units. The outlet of the first filter unit is connected to the inlet of the second filter unit to permit liquid sample to be pumped into the inlet of the first filter unit, through the cavity of each said filter unit, and discharged through the outlet of the second filter unit. A hose is respectively connected to each filtrate passageway of the first filter units respectively connected to inlet ports of a three way flow valve. A second conduit is connected to the outlet port of the three way valve. A timer is provided for actuating the three way valve.

What is claimed: 
     
       1. A self-cleaning filter combination, comprising: (a) a housing having an internal cavity;   (b) a liquid agitator means rotatably mounted within said cavity and adapted to be rotated by a rotating means external of said housing;   (c) a flat filter means mounted in supported relation between said housing and a connected housing cap with a filter face openly exposed to said cavity;   (d) said housing having inlet and outlet liquid flow passages for circulating a liquid sample through said cavity around said agitator and into filterable contact with said filter face;   (e) said agitator means having means to agitate said liquid sample within said cavity and to pump a portion of said liquid sample in a flow washing action against and across said filter face said agitator means comprises an agitator rotor having an irregular circumferential surface for agitating said liquid sample and also having a plurality of passageways inclined with respect to the axis of said rotor and disposed different radial distances away form said axis to cause a pumping action responsive to rotation of said rotor, said pumping action liquid sample in a flow washing action against and across said filter face; and   (f) said housing cap having a liquid filtrate passageway for withdrawing a filtered sample of said liquid sample through said filter means.   
     
     
       2. The combination of claim 1 wherein said flat filter means comprises a flat filter element providing said filter face and backed by a porous flat filter pad and a support plate. 
     
     
       3. A self-cleaning filter apparatus comprising: (a) a first filter unit and a second filter unit of the same combination as specified in claim 1;   (b) rotating means connected to concurrently drive the agitator means of said first filter unit and said second filter unit;   (c) conduit means connecting the outlet of said first filter unit to the inlet of said second filter unit whereby a liquid sample may be pumped into the inlet of said first filter unit, through the cavity of each said filter unit, and discharged through the outlet of said second filter unit;   (d) a hose respectively connected to each filtrate passageway of said first filter unit and said second filter unit and respectively connected to inlet ports of a three way flow valve;   (e) a second conduit connected to the outlet port of said three way valve; and   (f) timer means for actuating said three way valve between its first position and its second position and thereby to alternately withdraw filtered liquid sample from said first filter unit and said second filter unit and thereby to cause the filter face of each said filter unit to be alternately washed clean of filtered particles while the other filter face is receiving liquid sample to be passed to said three way valve.   
     
     
       4. The filter apparatus of claim 3 wherein the filter element of each said filter unit has 0.2 micron openings. 
     
     
       5. A self-cleaning filter apparatus including: (1.) a first filter unit, and   (2.) a second filter unit with each said filter unit comprising: (a) a housing having an internal cavity;   (b) a liquid agitator means rotatably mounted within said cavity and adapted to be rotated by a rotating means external of said housing;   (c) a flat filter means mounted in supported relation between said housing and a connected housing cap with a filter face openly exposed to said cavity;   (d) said housing having inlet and outlet liquid flow passages for circulating a liquid sample through said cavity around said agitator and into filterable contact with said filter face;   (e) said agitator means having means to agitate said liquid sample within said cavity and to force a portion of said liquid sample in a washing action across said filter face; and   (f) said housing cap having a liquid filtrate passageway for withdrawing a filtered sample of said liquid sample through said filter means.     (3.) rotating means connected to concurrently drive the agitator means of said first filter unit and said second filter unit;   (4.) conduit means connecting the outlet of said first filter unit to the inlet of said second filter unit whereby a liquid sample may be pumped into the inlet of said first filter unit, through the cavity of each said filter unit, and discharged through the outlet of said second filter unit;   (5.) a hose respectively connected to each filtrate passageway of said first filter unit and said second filter unit and respectively connected to inlet ports of a three way flow valve;   (6.) a second conduit connected to the outlet port of said three way valve; and   (7.) timer means for actuating said three way valve between its first position and its second position and thereby to alternately withdraw filtered liquid sample from said first filter unit and said second filter unit and thereby also to cause one filter face of each said filter unit to be alternately washed clean of filtered particles while the other filter face is receiving liquid sample to be passed to said three way valve.   
     
     
       6. The apparatus of claim 5 wherein said flat filter means comprises a flat filter element providing said filter face and backed by a porous flat filter pad and a support plate. 
     
     
       7. The apparatus of claim 5 wherein said agitator means comprises an agitator rotor having an irregular circumferential surface for agitating said liquid sample and also having a plurality of passageways inclined with respect to the axis of said rotor and disposed different radial distances away from said axis to cause a pumping action responsive to rotation of said rotor, said pumping action thereby forcing said portion of said liquid sample in a washing action across said filter face as specified. 
     
     
       8. The apparatus of claim 7 wherein the filter element of each said filter unit has 0.2 micron openings.